3-T proton magnetic resonance spectroscopy of central neurocytoma: 3 case reports and review of the literature.

Central neurocytoma (CNC), first described by Hassoun et al in 1982, is a rare neuronal tumor of the central nervous system, accounting for 0.25% to 0.5% of all central nervous system tumors. To our knowledge, there are only 5 published articles reporting the magnetic resonance spectroscopy (MRS) findings of neurocytomas. The 3-T proton MRS findings of 3 cases with CNC confirmed by immunohistochemical stains are reported here. Increased choline (Cho)/creatine (Cr) ratios with decreased N-acetylaspartate (NAA)/Cr ratios were observed in all 3 cases, but only 1 case had an increased peak at 3.55 ppm known as glycine (Gly). The other case with an increased alanine peak at 1.5 ppm had a poor prognosis. Therefore, we conclude that the presence of a Gly peak may suggest the diagnosis of CNC but that the absence of Gly does not exclude the diagnosis of CNC.